The LA Times has some questions:
Trump railed as a candidate and as president about people living in the country without permission, calling them rapists and violent gang members.
Last year, in a White House meeting discussing so-called sanctuary cities and states with sheriffs and other local California officials, the president said:

Comments
One response to “The list requested by the Secret Service as a security precaution”
If these undocumented workers are so dangerous and violent, it would seem essential that the Secret Service know about those that are surrounding the president. Which suggests (1) that the president is a lying hypocrite; or (2) that the golf club managers want to put the president at risk from violent, dangerous people in close proximity when he visits.
I’m going with 1, though I wouldn’t be surprised if people who work for Trump don’t like him much.